Mullerian-inhibiting substance reflects ovarian findings in women with polycystic ovary syndrome better than does inhibin B

Objective: To investigate Mullerian inhibiting substance (MIS) levels in women with polycystic ovary syndrome (PCOS)as well as relationships to ovarian morphology; levels of inhibin B, and other reproductive hormones. Design: Prospective clinical study. Setting: Academic endocrinology centers in Palermo, Italy and New York. Patient(s): Forty-six women with PCOS, recruited on the basis of the classic criteria of chronic anovulation and hyperandrogenism, and 25 age-matched ovulatory controls. Intervention(s): Fasting blood was obtained in all subjects in the early follicular phase (days 5-6) after spontaneous or induced menses (in PCOS), and transvaginal ultrasounds were performed. Main Outcome Measure(s): Assessment of values for luteinizing hormone (LH), testosterone (T), androstenedione (A), estradiol (E-2), inhibin B, MIS, fasting insulin, and the calculated quantitative sensitivity check index (QUICKI), as well as assessments of ovarian volume and blood flow. Result(s): Women with PCOS had higher LH, T; and A; higher insulin and lower QUICKI; and higher ovarian volume and lower pulsatility index. Inhibin B concentrations were statistically significantly higher in PCOS patients (70 +/- 8.0 vs. 40 +/- 3.4 pg/mL), as was MIS (6.7 +/- 0.9 vs. 4.6 +/- 0.5 ng/mL). Inhibin B had a statistically significant direct correlation with levels of MIS (r = 0.351). However, MIS, but; not inhibin B, had a statistically significant positive correlation with ovarian size (r = 0.350); the reproductive hormones LH, T, A, and E-2: and insulin (r = 0.249), independent of body mass index. Women with PCOS with the highest levels of MIS had higher ovarian volumes and values of LH, T, A, and insulin. Concluslon(s): Measurements of MIS reflect ovarian findings in PCOS better than levels of inhibin B and are more frequently elevated. However, MIS lacks sensitivity for use as a diagnostic tool in PCOS.